Monte Carlo Simulations

I am a core developer of the TOPAS Monte Carlo software. This is a user-friendly simulation software layered upon the general-purpose Geant4 particle transport toolkit. It was designed specifically for medical physics applications by MGH, Stanford and UCSF. Working on TOPAS has offered valuable insight into the current paradigm of proton therapy.

Here are some of the main features:

  • simulations are configured by user-friendly parameter files
  • geometry components, electromagnetic fields, particle sources and scorers are positioned in space
  • their parameters can also be changed in time (e.g. a rotating modulator wheel, moving MLC leaves)
  • other settings are also available (e.g. graphics, physics, variance reduction)
  • a versatile extension system enables users to add new features as needed

Full details can be found at

A proton therapy treatment head simulated in TOPAS.